mybatis中手动写sql，步骤是先在navicate中执行通过的sql，
如果是对象类型传参，需要注意jdbcType转换，比如：name = #{record.name,jdbcType=VARCHAR}
以下几种方法比较常用，欢迎补充。
1.pom.xml中mybatis依赖1.2.0
<dependencies> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.2.0</version> <exclusions> <exclusion> <groupId>org.apache.tomcat</groupId> <artifactId>tomcat-jdbc</artifactId> </exclusion> </exclusions> </dependency> <dependency> <groupId>com.zaxxer</groupId> <artifactId>HikariCP</artifactId> </dependency> <dependency> <groupId>com.github.pagehelper</groupId> <artifactId>pagehelper-spring-boot-starter</artifactId> <version>1.1.1</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-maven-plugin</artifactId> <version>1.3.2</version> <configuration> <overwrite>true</overwrite> <verbose>true</verbose> </configuration> </plugin> </plugins></build>
2.基本类型和对象参数，可以是这样：
ServerMapper.java:
int updateByExample(@Param("record") Server record, @Param("example") ServerExample example);
ServerMapper.xml:
<update id="updateByExample" parameterType="map"> update server set id = #{record.id,jdbcType=VARCHAR}, name = #{record.name,jdbcType=VARCHAR}, operatingsystem = #{record.operatingsystem,jdbcType=VARCHAR}, cpu = #{record.cpu,jdbcType=INTEGER}, applicant = #{record.applicant,jdbcType=VARCHAR}, status = #{record.status,jdbcType=VARCHAR} <if test="_parameter != null"> <include refid="Update_By_Example_Where_Clause" /> </if> </update>ServerMapper.java:
List<ServerDetails> selectByServerIds(List<String> serverIds);
ServerMapper.xml，注意collection为list:
<select id="selectByServerIds" resultMap="ServerDetailsMap"> SELECT s.id, s.`name`,s.operatingsystem,s.cpu,s.disksize,s.memorysize,s.intranetip,s.vcluster,s.`owner`,s.environment,s.applicant,s.`status`, ip.ip,ip.`status` as ipstatus, ip.segment,ip.remark,ip.line from `server` as s , ippool as ip where s.intranetip = ip.id and s.id in <foreach item="item" collection="list" open="(" separator="," close=")"> #{item} </foreach> </select>可以传递一个 List 实例或者数组作为参数对象传给 MyBatis。
当你这么做的时,MyBatis 会自动将它包装在一个 Map 中,用名称作为key。List 实例将会以“list” 作为key,而数组实例将会以“array”作为key。
ServerMapper.java文件中传入的是包含list的map，ServerMapper.xml中的collection为指定的excRelatedServerIds
Map<String, Object> map = Maps.newHashMap(); map.put("env", env); map.put("userId", userId); map.put("excRelatedServerIds", excRelatedServerIds); PageInfo<UserServerDetails> pageInfo = PageHelper.startPage(pageNum, pageSize).doSelectPageInfo(()-> serverMapper.selectPageByEnvAndUserExcRelated(map));ServerMapper.xml：
select us.id, us.user_id, us.server_id, s.`name`, s.operatingsystem, s.cpu,s.disksize,s.memorysize, s.intranetip, s.vcluster,s.`owner`,s.environment,s.applicant,s.`status`, ip.ip,ip.`status` as ipstatus,ip.segment,ip.remark , ip.line from user_server as us,`server` as s, ippool as ip where us.server_id = s.id and s.intranetip = ip.id <if test="env != null"> and s.environment=#{env,jdbcType=INTEGER} </if> <if test="userId != null"> and us.user_id=#{userId,jdbcType=VARCHAR} </if> and s.id not in <foreach item="item" index="index" collection="excRelatedServerIds" open="(" separator="," close=")"> #{item} </foreach></select>
5.还有一种是按照顺序传参数，这种不推荐：
Mapper.java：
Public User selectUser(String name,String area);
Mapper.xml ：
<select id="selectUser" resultMap="BaseResultMap">
select * from user_user_t where user_name = #{0} and user_area=#{1}
</select> 其中，#{0}代表接收的是dao层中的第一个参数，#{1}代表dao层中第二参数，更多参数一致往后加即可。
6.如果要封装自己的返回类型，需要xml文件中定义并且去引用bean对象：
<resultMap id="ServerDetailsMap" type="com.ServerDetails"> <id column="id" property="id" jdbcType="VARCHAR" /> <result column="name" jdbcType="VARCHAR" property="name" /> <result column="operatingsystem" jdbcType="VARCHAR" property="operatingsystem" /> <result column="cpu" jdbcType="INTEGER" property="cpu" /> <result column="disksize" jdbcType="INTEGER" property="disksize" /> <result column="memorysize" jdbcType="INTEGER" property="memorysize" /> <result column="intranetip" jdbcType="VARCHAR" property="intranetip" /> <result column="vcluster" jdbcType="VARCHAR" property="vcluster" /> <result column="owner" jdbcType="VARCHAR" property="owner" /> <result column="environment" jdbcType="INTEGER" property="environment" /> <result column="applicant" jdbcType="VARCHAR" property="applicant" /> <result column="status" jdbcType="VARCHAR" property="status" /> </resultMap>mybatis ${}与#{}的区别(来源网络)
#{} 解析的是占位符? 可以防止SQL注入，比如打印出来的语句 select * from table where id=?然而${} 则是不能防止SQL注入打印出来的语句 select * from table where id=2 实实在在的参数。
最简单的区别就是${}解析传过来的参数值不带单引号，#{}解析传过来参数带单引号。
最后总结一下必须使用$引用参数的情况，那就是参数的int型的时候，必须使用$引用。 参考：http://blog.csdn.net/u014687389/article/details/72778664?locationNum=8&fps=1 相关资源：敏捷开发V1.0.pptx